The present invention relates to exercise apparatus in particular to a sit-up belt for sit-up exercise on a bed.
Apparatus for sit-up exercise for use with bed are known in prior art.
One of these sit-up exercise apparatus is disclosed in U.S. Pat. No. 4,515,361 granted to Anthony Melillo et al. This apparatus includes two rectangular members pivotally connected together at repective ends thereof. One of these rectangular members is adapted to be inserted under a mattress in such a manner that the apparatus is retained under the mattress by frictional forces as well as by weight of the mattress. The other rectangular member is in the form of a rectangular frame with an adjustable bar which may be gripped by the hand or restrain the feet of a user in the performance of various exercise. This apparatus is too bulky and contains hard edges that may be harmful to a user during exercise.
Another sit-up exercise apparatus is disclosed in U.S. Pat. No. 4,378,939 granted to Norman W. Wild. This apparatus comprises an exerciser plate being adapted to attach to bed frame by means of pressure clamps and wing nuts, a pivot arm pivotally movable in relation to the exerciser plate, and an oval loop being connected to the pivot arm. There are many disadvantages of this apparatus. It is designed to permanently installed on a particular kind of metal bed frame. Therefore, it is not portable and the use is rather limited. It contains mainly of metal parts and has sharp metal edges which are harmful to a user during exercise.